The human-machine interface of any automated system, such as a computer or smart phone, requires provisions for accepting data entry from a user. Some examples of data entry devices include keyboards, cursor positioning devices, such as touch pads, joysticks, trackballs, and mice, and speech recognition systems.
Recent trends in user interfaces favor those containing speech recognition systems. Such user interfaces generally include software specially configured to interpret audio signals obtained from a microphone into digital codes according to a user's voice, speech patterns and pronunciation of words. Such systems generally require some level of training.